In a CDMA system, there is a strong relationship between system capacity, RF power, interference, and call quality. As call quality is increased, the power consumed by the system tends to increase. This situation consumes limited available cell power and increases system interference, which in turn reduces system capacity from an RF perspective. This is a particularly important aspect of efficient CDMA systems.
Call quality in this context includes voice quality which can be measured by frame erasure rate; mean opinion score (MOS score) which is a measure of voice quality; data throughput for data services; and call reliability which includes call setup success rate and the dropped call rate. This relationship is well known to those skilled in the art. Therefore, there is a fundamental tradeoff between call performance (FER/quality, call reliability, and messaging reliability) and system capacity. As the link performance is increased FER is typically lowered, additional power is consumed, interference is generated, and capacity is reduced.
For establishing and maintaining voice communication between cellular users, control or signaling messaging is required. A traffic channel carries, among other things, voice packets of each person speaking as well as signaling and control messaging such as handoff related messaging for a cellular subscriber moving from one cell to another. While the prior art focuses on boosting certain types of control messages, the prior art fails to distinguish between circumstances in which a certain type of control message may or may not be boosted.
Control messages must be reliably transmitted in a fast manner in order to achieve good call performance, that is, a low dropped call rate and low noise RF traffic channels. One method to increase such call performance is to quickly or rapidly repeat certain call critical messages. Quick repeating is a process of sending the same message multiple times in rapid succession in order to increase the likelihood that a particular message will be received reliably by the mobile unit.
Existing communications that address this problem provide a static mechanism for quickly repeating call critical control messages. These methods do not take into account voice quality impacts or data throughput. Existing methodology may quickly repeat critical messages in a static fashion, but this typically has a negative impact on voice quality.
Accordingly, it would be desirable to have a method of selective need-based control message augmentation not found in the prior art.
Elements in the Figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the Figures may be exaggerated relative to other elements to help improve understanding of various embodiments of the present invention. Furthermore, the terms “first”, “second”, and the like herein, if any, are used inter alia for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. Moreover, the terms “front”, “back”, “top”, “bottom”, “over”, “under”, and the like in the Description and/or in the Claims, if any, are generally employed for descriptive purposes and not necessarily for comprehensively describing exclusive relative position. Any of the preceding terms so used may be interchanged under appropriate circumstances such that various embodiments of the invention described herein may be capable of operation in other configurations and/or orientations than those explicitly illustrated or otherwise described.